Several groups have investigated antimicrobial coated polyurethane. See the attached links for more detailed information.

http://jco.ascopubs.org/content/22/15/3163.full.pdf

http://www.ncbi.nlm.nih.gov/pubmed/15265557

http://jco.ascopubs.org/content/22/15/3163.full.pdf

HI, silver nano particles have been incorporated in HDPE (during manufacturing process) and show significant anti microbial activity.  Maybe this will work in your case too. 

Actually, there is a medical clothing impregnated with pyrithione zinc, you can review this patente "Contacting with pyrithione acid or salts on transfer sheet

US 5154947 A"

Copper salts or nanoparticles have very good results depending on the carrier you use.

Nano particles or natural oils could be options. 

Prevention of polyurethane device colonisation and infection is considered to be an important area of risk reduction.  Antimicrobial bonding, coating and impregnation of intravascular devices have emerged as important risk reduction strategies and as a result several antimicrobial-coated or impregnated catheters have been developed for clinical use.

With further advances in healthcare we turn to strategies of higher technology including the use of surface engineering and nanoparticles.  A number of antimicrobial, antifungal and antiseptic agents have been successfully employed to coat or impregnate polyurethane device surfaces for prevention of microbial colonisation, biofilm formation and infection. 

The following are some examples with references:

Rifampicin + Minocycline

Rifampicin + Miconazole

Vancomycin

Cefazolin

Silver sulfadiazine + Chlorhexidine

Silver zeolite

Alcohol

Nano particles

Silver, platinum, or carbon coating

References

1. Pratt RJ, Pellowe C, Loveday HP, Robinson N, Smith GW, Barrett S, et al. The epic project: developing national evidence-based guidelines for preventing healthcare associated infections. Phase I: Guidelines for preventing hospital acquired infections. Department of Health (England). J Hosp Infect 2001 Jan;47(Suppl.):S3e82.

 2. Pearson ML, Abrutyn E. Reducing the risk for catheter related infections: a new strategy. Ann Intern Med 1997; 127(4):304e6.

 3. Wenzel RP, Edmond MB. The evolving technology of venous access. N Engl J Med 1999;340(1):48e50.

 4. Maki DG, Stolz SM, Wheeler S, Mermel LA. Prevention of central venous catheter-related bloodstream infection by use of an antiseptic-impregnated catheter. A randomized, controlled trial. Ann Intern Med 1997;127(4):257e66.

 5. Darouiche RO, Raad II, Heard SO, Thornby JI, Wenker OC, Gabrielli A, et al. A comparison of two antimicrobialimpregnated central venous catheters. Catheter Study Group. N Engl J Med 1999;340(1):1e8.

 6. McGee WT, Moriarty KP. Accurate placement of central venous

catheters using a 16-cm catheter. J Intensive Care Med 1996;11(1):19e22.

 7. Anonymous. Multicath expert and AGIon technology. Vygon (UK) Limited; 26/01/2001.

 8. Khare MD, Bukhari SS, Swann A, Spiers P, McLaren I, Myers J. Reduction of catheter-related colonization by the use of a silver zeolite impregnated central vascular catheter in adult critical care. J Infect. 2007;54(2):146-150. 37

I trust that this information is of some help.

Best wishes

Sayed S Bukhari MD FRCPath

Consultant in Infection

Midlands

UK